Toe iron for safety ski bindings

ABSTRACT

A soleholder member constitutes the coupling link of a four-bar linkage, which comprises two-armed levers that are connected to a carrier, which is pivoted to a baseplate that is fixed to the ski. The distance between the fulcrums of the levers exceeds the distance between the pivotal axes of the soleholder member. That arm of each lever which does not carry the soleholder member forms a locking member, which cooperates with a stop that is rigid with the baseplate. When the soleholder member is in its normal position, said locking members lock the carrier against a pivotal movement to respective sides. A spring is held on the carrier and opposes a pivotal movement of the four-bar linkage from its normal position.

[ 1 Aug. 8, 1972 [54] TOE IRON FOR SAFETY SKI BINDINGS [72] Inventor: Hans Otto Frisch, Blumenstrasse 4,

8105 Farchant, Germany [22] Filed: June 9, 1979 [21] Appl. No.: 44,811

[30] Foreign Application Priority Data June 19, 1969 Germany ..P 19 30 997.8

[52] US. Cl. ..280/ll.35 T [51] Int. Cl ..A63c 9/00 [58] Field of Search ..280/l1.35 T

[56] References Cited UNITED STATES PATENTS 2,846,232 8/1958 Schnell; ..2s0/11.3s T 3,348,855 10/ 1967 Marker ..280/ l 1.35 T 3,528,672 9/1970 Wunder ..280/l 1.35 T

Primary Examiner-Benjamin Hersh Assistant Examiner-Robert R. Song Attorney-Fleit, Gipple & Jacobson [57] ABSTRACT A soleholder member constitutes the coupling link of a four-bar linkage, which comprises two-armed levers that are connected to a carrier, which is pivoted to a baseplate that is fixed to the ski. The distance between the fulcrums of the levers exceeds the distance between the pivotal axes of the soleholder member. That arm of each lever which does not carry the soleholder member forms a locking member, which cooperates with a stop that is rigid with the baseplate. When thesoleholder member is in its normal position, said locking members lock the carrier against a pivotal movement to respective sides. A spring is held on the carrier and opposes a pivotal movement of the fourbar linkage from its normal position.

7 Claims, 7 Drawing Figures PATENTEDAUG 81972 SHEET 1 [IF 3 INVENTORI Hans -0o Fn'sek PATENTEDAUB slave 3.682.494

SHEET 3 [IF 3 TOE IRON FOR SAFETY SKI BINDINGS The present invention relates to a toe iron for safety ski bindings, which toe iron comprises a soleholder member which constitutes the coupling link of a fourbar linkage, which comprises two-armed levers that are connected to a carrier, which is pivoted to a baseplate that is fixed to the ski, and in which toe iron the distance between the fulcrums of the levers exceeds the distance between the pivotal axes of the soleholder member.

In these known toe irons, a ball detent lock is provided between the soleholder member and the baseplate and the said lock is held closed by a variable pressure so that the force required fora release can be varied. Those arms of the leverswhich do not carry the soleholder member serve as actuating means, by which an additional lock which is provided between the carrier and the baseplate is opened after a predetermined movement of the soleholder member.

Owing to the use of the four-bar linkage, this toe iron has the advantage that the soleholder member is moved along an are which is centered on the imaginary axis of rotation of the skiing boot. As a result, a pivotal movement of the soleholdermember does not impart to the skiing boot a component of motion toward the tip of the ski under the influence of the force which acts on the heel and urges the skiing boot against the toe iron.

This toe iron has the disadvantage that its soleholder member is locked on the baseplate so that the toe iron is highly susceptible to shock. Because the skier is afraid of the resulting unnecessary release actions and falls and the atypical skiing injuries caused thereby, he is tempted to select an excessively hard setting for the toe iron so that it may fail to release in a critical instance and typical skiing injuries may result which ought to have been avoided by the safety binding.

It is an object of the present invention so to improve and design a toe iron of the kind defined first hereinbefore for ski bindings that the toe iron is notsusceptible to shock and nevertheless does not involve an increased expenditure and cost.

In a toe iron for safety ski bindings, which toe iron in a common horizontal plane, to arrange each lever arm which forms a locking member so that its outer end face forms a stop for the anti-friction bearing, and that each stop is curved about the fulcrum of the respective lever. The carrier may be formed with a curved slot,

which has a center of curvature on the pivotal axis of the carrier; in this case, the stop which is rigid with the baseplate extends through the slot and its free end portion carries the anti-friction bearing.

' In a special development of the invention, the spring bears on the carrier by means of a bearing element, which has two bearing points disposed on opposite sides of the vertical longitudinal center plane and which is pivotally movable in a horizontal direction about one or the other of said bearing points against the I force of the springQThis arrangement results in particucomprises a soleholder member which constitutes the 1 coupling link of a four-bar linkage, which comprises two-armed levers that are connected to a carrier, which is pivoted to a baseplate that is fixed to the ski, and in which toe iron the distance between the fulcrums of the levers exceeds the distance between the pivotal axes of the soleholder member, this object is accomplished according to the invention in that that arm of each lever which does not carry the soleholder member fonns a locking member, which cooperates with a stop that is rigid with the baseplate, said locking members lock the carrier against a pivotal movement to respective sides when the soleholder member is in its normal position, and a spring is held on the carrier and opposes a pivotal movement of the four-bar linkage from its normal position.

Contrary to the known toe irons, the toe iron according to the invention may be so designed that it will automatically return to its normal position after a safety release.

It has been proved desirable to provide an antifriction bearing, which is carried by the stop that is rigid with the baseplate, to arrange the lever arms which form the locking members and the anti-friction bearing larly desirable force transmission ratios. Different forces may be required for a release toward both sides if, in a development of this feature of the invention, the distance of v the bearing points of the bearing element from the vertical longitudinal center plane is variable.

The bearing point of the spring on the carrier is suitably adjustable in the longitudinal direction of the carrier in order to pennit of a change of the force required for a release of the toe iron.

If the spring extends horizontally in a central vertical plane when the toe iron is in its normal position, each of those arms of the levers which carry the soleholder member comprises preferably an inwardly extending nose, which is acted upon by the spring with a spring abutment interposed, if desired.

Another feature of theinvention is applicable to special advantage to a toe iron of the kind described hereinbefore, the sole-engaging element may be mounted on the soleholder member fora free vertical sliding movement and may be formed with a horizontal groove in a surface which faces a surface of the soleholder member which latter surface is formed with a series of horizontal grooves, and a locking pin may be received in said groove of the sole-engaging element and one of the grooves of the soleholder member. With this arrangement, the sole-engaging element may easily be adapted to skiing boot soles having different thicknesses. To prevent an undesired disengagement,

the free end portion of the locking pin is preferably angled and the sole-engaging element may be provided with a recess for receiving said end portion.

An embodiment of the invention will now be described more fully and by way of example with reference to the accompanying drawings, in which FIG. 1 is a central longitudinal sectional view showing a toe iron, I

FIG. 2 is a top plan view showing the toe iron of FIG. 1,

FIG. 3 is a top plan view which is similar'to FIG. 2 but shows the toe iron in position immediately before a safety release,

FIG. 4 is a top plan view showing the toe iron in open position,

FIG. 5 is a side elevation of the toe iron,

FIG. 6 is a top plan view of an arrangement in which the means which support the spring on the carrier differ from those of FIGS. 1 to 5, and

FIG. 7 shows the toe iron of FIG. 6 in a position which corresponds to that of FIG. 3.

The toe iron according to the inventioncomprises a baseplate 1, by which the toe iron can be connected to a ski, e.g., by screws. For this purpose, the baseplate is formed with two countersunk holes 2 (see FIGS. 2-4). The baseplate isprovided witha pivot pin 3 (see particularly FIG. 1), on which a carrier 4 is pivotally mounted. The carrier is held against axial movement by a disc 5, which is screwed by means of a screw 6 to the pivot pin. Two levers 9, 10 are mounted at the pivots 7, 8 on the carrier and are connected at the pivots 12, 13

m soleholder member 11 and'together with the latter 1 form a four-barlinkage; At its "end opposite to the soleholder member, the carrier 4 comprises offset portions '14, which serve as guide rails and protrude into a corresponding groove 15 of the soleholder memberll 7 (see particularly FIGS. 1 and 5).

The levers 9, 10 are two-armed and their arms 16 and l7which do not carry the soleholdermember constitute respective; locking members; The two locking members cooperate with an anti-friction bearing 18,

which constitutes'a stop that is rigid with the baseplate.

,The bearing 18 is mounted on a' 'carrying pin 19, which is 'rivetedinto-the baseplate 1 (see FIG. 1). In the normal position of the soleholder member 1 1, each locking bolt locks the carrier 4 against a pivotal movement to one side. Otherwise, such movement of the carrier would be. permitted by a correspondingly curved slot 40. That end of the carrier 4 which is remote from the soleholder-member l l-forms a guide 20 fora bearing 3 bracket 21. The 'guide 20 extends in the'longitudinal direction of the carrier. Thebearing bracket 21 can adjusted in the guide 20 by means'of a screw 22. A spring abutment 24 is held in anannular groove 23 of the bearing bracket 21 and provided with a spring-'guiding pin 25. A helical compression spring 26 bears at one end on the spring abutment 24, and at its other end on a'spring abutment 28, which is also vprovided with a spring-guiding pin 27 and which on its outer end face is formed with two notches, each of which receivesa nose 29 or 30. The nose 29 is formed on that arm of the lever 9 which carriesthe soleholder member 1 1 and the nose 18. Upon a decrease of the force, the helical compression spring 26 returns the four-bar linkage to the normal position shown in FIG. 2.

If a force which exceeds the predetermined force required for a release acts on the soleholder member 1 1 not only as a shock, the four-bar mechanism will initially move again in the manner which has been described hereinbefore. After a'predetermined pivotal movement, the extent of which depends on the design of the toe iron, the outer end face of the arm 17 of the lever 10 disengages the anti-friction bearing 18 so that the carrier 4 is unlocked andcan now move about the pivot pin 3 to the position shown in FIG. 4; During this second phase of the movement, the soleholder member virtually suddenly releases the toe portion of the skiing boot. In this embodiment shown by way of example, the

stress of the helical compression spring 26 is not increased in this second phase of the operation so that a seizing of the skiing bootin an oblique position on "the ski is reliably avoided. Because the stress of the spring is notinc'reased inthe second phase of 'the'opening movement of the toe iron, the carrier must'be swung back by handto its normal position to retum the toe iron to its position for skiing. When the carrier has been swung back to its normal position, the four-bar linkage is automatically returned by the helical compression spring 26.

In the second phase'of the releaseoperation, the I anti-friction bearing 18 rolls on the outer end face of the lever arm 17. When the toe iron should return automatically to its normal position whenthe boot has been released, the outer end'facesof the lever arms 16,717

30 is formed on the correspondingarm of thelever l0 (see particularly FIG. 2). I

FIGS. '1, 2 and 5 show the toe iron in its normal position, in which the carrier 4-is locked against a pivotal movement on the baseplate l. arms 16 and 17 of Y the levers 9 and 10 which serve as locking members have curved outer end faces which are centered on the respective fulcrum 7 or 8 and extend adjacent to the anti-friction bearing 18, which serves as a stop that is rigid with the baseplate. The four-bar linkage is centered in its normal position by the helical compression spring 26, which is more or less highly prestress'ed as may be required.

When the soleholder member 11 is acted upon by a I force in a direction which is transverseto the longitudinal direction of the toe iron, e.g.,. in *a downward direction in FIGS. 2 to 4 of the drawing, and this force exceeds the initial stress of the helical compression I spring, the four-bar linkage will be movedagainst the force of the spring, as is shown in FIG. 3. The stress of the spring will then be increased bythe nose 29 of the lever9. The carrier 4 remains in its normal position in this phase because the free end of the arm 17 of the lever 10 is still in contact with the anti-friction bearing may be curved with such a small radius that the stress of the helical compression spring is slightly increased during the second phase-of the movement by'a small bearing member'35, which bears on both bearing pins 32, 33 when the toe iron is in normal position (see F IG. 6). The bearing member is located by two recesses, which have the same curvature as the bearing pins and vare spaced apart by the same distance as the bearing pins. When the soleholder member is acted upon by a force which exceeds the resistance presented by the spring, the bearing member is swung about the bearing pin on that side to which the soleholder member is moving (see FIG. 7). This design may be adopted to provide particularly. desirable force transmission ratios.

In accordance with a special feature of the invention, the sole-engaging element 41 is mounted on the soleholder member 11 for a free vertical'sliding movement. Thesoleholder member is formed in its surface 42, which faces the soleholder element, with a series of horizontally extending grooves 43. A corresponding horizontal groove 44 is formed in the sole-engaging element and together with a registering groove 43 receives a locking pin 45, which is insertable from the side.

When it has been removed, the sole-engaging elementis slidable on the soleholder member for adjustment to skiing boot soles differing in thickness. The locking pin consists of a piece of spring wire, which has a pointed end portion and an angled opposite end portion 46. The sole-engaging element is formed with a recess 47 for receiving said angled end portion. During its insertion into the grooves, the locking pin is held so that its angled end portion extends approximately horizontally. When the locking pin has been introduced, the angled end portion is turned upwardly so that the locking pin is seized in position. The angled end portion is then engaged with the recess of the sole-engaging element to lock the locking pin against an unintended release.

What is claimed is:

l. A toe iron for safety ski bindings, which toe iron comprises a four-bar linkage and a baseplate fixed to the ski, said baseplate having a vertical pivot pin fixedly mounted on the rearward central portion thereof, a carrier pivotally connected to the baseplate about said pivot pin, and said four-bar linkage including a pair of laterally spaced two-armed levers and a transversely extending soleholder member acting as a coupling link between said levers, each of said levers being pivotally mounted to said carrier about respective pivot axes positioned forwardly of said pivot pin, each of said levers being further pivotally connected at its rearward end to said coupling link about respective coupling link pivot axes, and wherein the distance between the pivot axes of the levers exceeds the distance between the coupling link pivot axes, said toe iron further comprising a stop rigidly connected to said baseplate at a forward central portion thereof forwardly of said lever pivot axes, the forward end of each of said levers forming a locking member normally engaging said stop, said locking members locking the carrier against a pivotal movement to respective sides when the soleholder member is in its nonnal position, and the forward end of said carrier having a guide member rigidly connected thereto, a longitudinally adjustable bearing bracket carried in said guide member, the rearward end of each of said levers having a nose portion extending inwardly toward the longitudinal center line of said toe iron, a compression spring positioned with the forward end of said spring abutting against said bearing bracket and the rearward end of said spring abutting against said nose portions, and said spring opposing a pivotal movement of the four-bar linkage from its normal position.

2. A toe iron according to claim 1, wherein the stop comprises an anti-friction bearing, said locking members and the anti-friction bearing located in a common horizontal plane, each of said locking members having an outer end face acting as a stop for the anti-friction bearing, and each said outer end face being centered about a respective one of said lever pivot axes.

3. A toe iron according to claim 2 characterized in that the carrier is formed with a curved slot, which has a center of curvature on the pivotal axis of the carrier at said pivot pin, and the stop which is rigid with the baseplate extends through the slot and wherein the stop has a free end portion which carries the anti-friction bearing.

4. A toe iron according to claim 1, in which the spring extends horizontally in a central vertical plane g A t gfidr i a b di diiig i i iriii iii fher comprising spring guide pins defining a forward spring abutment and a rearward spring abutment, said spring guide pins positioned between said bearing bracket and said nose portions.

6. A toe iron according to claim 5, characterized in that the distance between said forward and said rearward spring abutrnents is adjustable in the lingitudinal direction of the carrier.

7. A toe iron according to claim 1 wherein the bearing bracket has two bearing pins disposed on opposite sides of a vertical longitudinal center plane of said toe iron, and said toe iron further comprising a bearing member connected to said spring and having two recesses for normally engaging said bearing pins, said bearing member being pivotally movable in a horizontal direction about one or the other of said bearing pins, said spring bearing on said bearing member to oppose movement of the bearing member against the force of the spring.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Pat 8 9 Dated August 8, 1972 Inventor(s) HANS OTTO FRISCH It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the title page, insert [73] Assignee: Hannes Marker Garmisch-Partenkirchen Germany Signed and sealed this 9th day of January 1973.

(SEAL) Attest:

EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents FORM (10-69) USCOMMDC 6O376-P69 [1.5. GOVERNMENT PRINTING OFFICE I I959 0-355334 

1. A toe iron for safety ski bindings, which toe iron comprises a four-bar linkage and a baseplate fixed to the ski, said baseplate having a vertical pivot pin fixedly mounted on the rearward central portion thereof, a carrier pivotally connected to the baseplate about said pivot pin, and said four-bar linkage including a pair of laterally spaced two-armed levers and a transversely extending soleholder member acting as a coupling link between said levers, each of said levers being pivotally Mounted to said carrier about respective pivot axes positioned forwardly of said pivot pin, each of said levers being further pivotally connected at its rearward end to said coupling link about respective coupling link pivot axes, and wherein the distance between the pivot axes of the levers exceeds the distance between the coupling link pivot axes, said toe iron further comprising a stop rigidly connected to said baseplate at a forward central portion thereof forwardly of said lever pivot axes, the forward end of each of said levers forming a locking member normally engaging said stop, said locking members locking the carrier against a pivotal movement to respective sides when the soleholder member is in its normal position, and the forward end of said carrier having a guide member rigidly connected thereto, a longitudinally adjustable bearing bracket carried in said guide member, the rearward end of each of said levers having a nose portion extending inwardly toward the longitudinal center line of said toe iron, a compression spring positioned with the forward end of said spring abutting against said bearing bracket and the rearward end of said spring abutting against said nose portions, and said spring opposing a pivotal movement of the four-bar linkage from its normal position.
 2. A toe iron according to claim 1, wherein the stop comprises an anti-friction bearing, said locking members and the anti-friction bearing located in a common horizontal plane, each of said locking members having an outer end face acting as a stop for the anti-friction bearing, and each said outer end face being centered about a respective one of said lever pivot axes.
 3. A toe iron according to claim 2 characterized in that the carrier is formed with a curved slot, which has a center of curvature on the pivotal axis of the carrier at said pivot pin, and the stop which is rigid with the baseplate extends through the slot and wherein the stop has a free end portion which carries the anti-friction bearing.
 4. A toe iron according to claim 1, in which the spring extends horizontally in a central vertical plane when the toe iron is in its normal position.
 5. A toe iron according to claim 1 further comprising spring guide pins defining a forward spring abutment and a rearward spring abutment, said spring guide pins positioned between said bearing bracket and said nose portions.
 6. A toe iron according to claim 5, characterized in that the distance between said forward and said rearward spring abutments is adjustable in the lingitudinal direction of the carrier.
 7. A toe iron according to claim 1 wherein the bearing bracket has two bearing pins disposed on opposite sides of a vertical longitudinal center plane of said toe iron, and said toe iron further comprising a bearing member connected to said spring and having two recesses for normally engaging said bearing pins, said bearing member being pivotally movable in a horizontal direction about one or the other of said bearing pins, said spring bearing on said bearing member to oppose movement of the bearing member against the force of the spring. 